Podcaster: Dr. Al Grauer


Title: Travelers in the Night Eps. 181E & 182E: Survivor & Star Wanderer

Organization: Travelers in The Night

Link : Travelers in the Night ; @Nmcanopus

Description: Today’s two stroy:

  • Rik Hill discovered car-sized 2015 SK7.
  • Richard Kowalski discovered Comet C/2013 US10 (Catalina) which is being ejected from our solar system.

Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona.  This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.

He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.

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181E: Survivor

Thirty six hours before my Catalina Sky Survey teammate Rik Hill discovered it, a space rock about size of a Toyota Prius passed about 14,000 miles above the Earth’s surface.  When Rik first spotted it this small asteroid was about a million miles from us and was moving away from the Earth at 12.6 miles per second. Its orbit had been changed by a narrow escape from the Earth’s gravity and it was on a new path around the Sun  This small space rock was subsequently observed by telescopes in Russia and Arizona.  The Minor Planet Center used these observations to calculate an orbit and give it the name 2015 SK7.  

All asteroids have a lighted side which is facing the Sun and a dark side which is pointing away from the Sun. Asteroid 2015 SK7 approached from close to the direction of the Sun in the sky with only 6% of its lighted side facing towards planet Earth.  This geometry caused it to brighten more than 10,000 times in 4 hours as it streaked by us at 13.6 miles per second.  No one saw it when it was closest to us even though it was bright enough to be recorded by a backyard telescope equipped with an electronic camera.  A small space rock of this size enters our atmosphere about once every year or two.  When one does it typically may be visible for a few minutes before it explodes 25 miles above the the Earth’s surface raining pieces onto the ground. 

182E: Star Wanderer

From the dawn of history, humans have longed to wander amongst the stars. Now we know that comets are able to make such a voyage giving us paths to follow. 

From late November of 2015 through January of 2016 Comet C/2013 US10 (Catalina) is predicted to be visible to the naked eye. My Catalina Sky Survey teammate Richard Kowalski discovered this interesting object in 2013.  Observations by telescopes around the world have shown that this Comet is being ejected from our solar system.

NASA scientists have suggested that the first interstellar robotic spacecraft could be propelled by a solar sail as large as the state of Texas.  Such a mission, perhaps two or three hundred years into the future could follow a comet’s path.  In this flight of fantasy the spaceship would be inclosed in a reflective spherical heat shield, placed into a Sun grazing orbit, and flung by the Sun’s gravity onto a path which will cause it to be ejected from the solar system. After getting to a safe distance from the Sun the robotic spacecraft would deploy its solar sail and use light pressure to accelerate towards its destination.  It could be further helped along using a powerful laser projected from the far side of the Moon. In a few decades or maybe even a few centuries it would arrive in a nearby solar system.  After that it would be on its own to try to make sense of what is there and to beam information back to its human creators.

Back to science reality.  Take the time to look at Kowalski’s object, C/2013 US10 (Catalina) as it passes through our solar system on its way to the stars.

For Travelers in the Night this is Dr. Al Grauer

End of podcast:

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